This invention relates generally to bedding and, more particularly, to a bedding foundation having a nestably stackable spring assembly.
Bedding foundations, or so-called box springs, generally include a base and an upper grid including a generally rectangular border wire between which coil or bent wire spring modules are located. As thus manufactured, these box spring assemblies are bulky and shipping them to the manufacturer for application of padding and covering thereto is costly because of space requirements. To reduce the space requirements, it is customary to compress the assemblies to reduce their individual thicknesses and to tie them in their compressed state. This involves using presses and ties which are expensive, and the extra operations of pressing and tying the assemblies also adds to their manufacturing cost. At the delivery end, the manufacturer must cut and discard the ties before applying the covering. These additional material and handling expenses increase the end cost of box spring assemblies.
Box spring assemblies by their very nature are intended to provide a stable support foundation for mattresses or other bedding placed on top thereof. Toward that end, the components used in the box spring assemblies should be securely and firmly mounted in the assembly to avoid any wobble or shifting during use.
U.S. Pat. Nos. 5,052,064 and 7,237,282 disclose bedding foundations having nestably stackable spring assemblies which may reduce shipping costs. However, each of the foundations disclosed in these patents has an upper border wire having a round cross-sectional configuration.
The border wire of these and other known bedding foundations is often three-gauge having a diameter of 0.243 inches. To make a border wire having the same beam strength, but made from a smaller diameter wire, say four-gauge wire having a diameter of 0.224 inches, would save material and therefore reduce the end cost of the foundation. In order to achieve the same beam strength, the four-gauge border wire must be changed or shaped from a circular cross-section to a rectangular cross-section in accordance with the present invention. Thus, the present invention enables one to use a four-gauge wire rather than a three-gauge wire in the border wire of the bedding foundation and therefore, reduce wire cost without giving up any beam strength.
In order to achieve cost savings, it would be desirable to reduce the cross-sectional area of the border wire of a bedding foundation (by creating the border wire from a smaller diameter wire) while maintaining the same beam strength or increasing it.
Therefore, a bedding foundation having a nestable, stackable spring assembly, including a border wire with a rectangular cross-section that can be stacked for shipping without having to compress and tie the spring assembly, would be a significant improvement.